Vegan: no creature is killed for your dining benefit, no honey, no dairy, no eggs, no leather..
Vegetarian: no creature is killed for your dining benefit. Usually won't do leather, but sometimes there's not much of a choice (dancers who aren't famous enough to have Capezio make man-made, high-end, shoes, for instance)
Ovo Lacto vegetarian: the way we have to explain ourselves for those confused between the above because of people who aren't vegetarian saying they are. A lady at my WW meeting goes on and on about being vegetarian, then talks about this crab dish she loves. AUGH.
I, too, don't EVER want anyone else worrying about my food. The only info the friend needs is "yes they will make you pasta or let you have the mac n cheese if either is acceptable", and move on.